Acetaminophen Dosing for a 44-Pound Child
Give 10 mL (320 mg) of acetaminophen 160 mg/5 mL suspension every 4–6 hours as needed, not exceeding 5 doses in 24 hours.
Weight-Based Calculation
A 44-pound child weighs approximately 20 kg (44 lb ÷ 2.2 = 20 kg). 1
The standard dose is 10–15 mg/kg per dose, with the American Academy of Pediatrics recommending this range for safe and effective antipyresis and analgesia. 1
For a 20 kg child, this translates to 200–300 mg per dose. 1
Using the 160 mg/5 mL suspension:
- Minimum dose (10 mg/kg): 200 mg = 6.25 mL
- Standard dose (15 mg/kg): 300 mg = 9.4 mL (round to 10 mL)
- Maximum single dose: 300 mg = 9.4 mL 1
Dosing Frequency and Safety Limits
Administer every 4–6 hours as needed for fever or pain. 1
Maximum daily dose: Never exceed 60 mg/kg per day (1,200 mg/day for this 20 kg child) or 5 doses in 24 hours, whichever is lower. 1
The oral suspension is preferred over rectal suppositories because it provides more rapid and consistent absorption. 1
Practical Dosing Recommendation
The most practical approach is to give 10 mL (320 mg) every 4–6 hours, which delivers 16 mg/kg—slightly above the standard 15 mg/kg but well within safe limits and supported by pharmacokinetic modeling showing that 15 mg/kg is necessary to achieve therapeutic plasma concentrations (10–20 μg/mL) for effective antipyresis. 2
Research demonstrates that 10 mg/kg doses often fail to reach therapeutic plasma concentrations, while 15 mg/kg is more reliably effective. 2
Age-based dosing (which many manufacturers use) frequently results in underdosing, with studies showing 27% of children receive inadequate amounts when parents don't use weight-based calculations. 3, 4
Special Circumstances Requiring Dose Reduction
Reduce to 10 mg/kg (6.25 mL or 200 mg) if the child has:
- Chronic malnutrition or has fasted for more than 8 hours without adequate caloric intake 1
- Pre-existing liver disease 1
- Concurrent use of cytochrome P450-inducing medications (e.g., isoniazid) 1
Common Pitfalls to Avoid
Do not use age-based dosing from manufacturer labels—weight-based dosing is significantly more accurate and prevents both underdosing and overdosing. 4
Avoid dosing more frequently than every 4 hours, as this increases toxicity risk without additional benefit. 1
Do not exceed 5 doses in 24 hours, even if individual doses are within range, to prevent cumulative hepatotoxicity. 1
Parents frequently misdose acetaminophen, with 62% giving inaccurate amounts in one emergency department study; clear written instructions with milliliter measurements (not teaspoons) reduce errors. 4